Respuesta :

The answer of 18 is y = 0.5x + 0

The answer of 22 is y =  -0.4x + 0

Step-by-step explanation:

c is constant, m is gradient

18. m = 1/2

     m = 0.5

     1 = 0.5(2) + c

     1 = 1 + c

     c = 0

     y = 0.5x + 0

22. m = 2/-5

      m = -0.4

      2 = -0.4(-5) + c

      2 = 2 + c

      c = 0

      y = -0.4x + 0